Thermal rotary link

ABSTRACT

An example apparatus may include a first plate having a first side. A first plurality of fins may be integral with the first side of the first plate and protruding perpendicularly therefrom. The first plurality of fins may be arranged in first concentric circles separated radially by a first distance. The apparatus may also include a second plate having a first side. The second plate may be rotatably coupled to the first plate. A second plurality of fins may be integral with the first side of the second plate and protruding perpendicularly therefrom. The second plurality of fins may be arranged in second concentric circles separated radially by the first distance. Each fin of the second plurality of fins may interpose between adjacent fins of the first plurality of fins to transfer heat between the second plate and the first plate.

BACKGROUND

Heatsinks are passive heat exchangers that transfer and dissipate heatgenerated by an electronic or mechanical device away from the device tomaintain the device at an appropriate operating temperature. Thegenerated heat may be dissipated to a fluid medium such as ambient airor liquid coolant. Heatsinks are commonly used with high-powersemiconductor devices and optoelectronics such as lasers and lightemitting diodes (LEDs), where the heat dissipation characteristics ofthe components itself is insufficient to maintain the component at asafe and stable temperature during operation. To increase the heatdissipated by the heatsink, the surface area of the heatsink in contactwith the surrounding cooling medium may be increased or maximized.Additionally, heat dissipation may be improved by manufacturing the heatsink from thermally conductive materials such as aluminum. Further,fluid may be forced over the heatsink by way of a fan or propeller tomaintain a large temperature difference between the heatsink and thesurrounding fluid.

SUMMARY

In an example embodiment, a thermal rotary link is configured totransfer heat between two or more devices, systems, or objects inrotational motion with respect to one another. The thermal rotary linkmay include a rotor and a stator, each including a respective plate anda plurality of fins protruding perpendicularly from the respectiveplate. The rotor and the stator may be rotatably connected together by arotational joint. The plurality of fins may be arranged in concentriccircles so that fins of the rotor may interpose with fins of the stator.The plurality of fins may be designed to increase or maximize a surfacearea exposed between fins of the rotor and fins of the stator. When thefins of the rotor and fins of the stator are interposed with oneanother, heat may be transferred from the fins of the rotor to fins ofthe stator by way of an air gap separating adjacent fins. The rotor andstator may be used to transfer heat from a heat source such as arotating LIDAR device to a cooling device. In some embodiments, therotor and stator may be disposed within a sealed chamber filled with athermally conductive fluid to improve heat transfer between fins of therotor and fins of the stator.

In one embodiment, an apparatus is provided that includes a first platehaving a first side and a first plurality of fins integral with thefirst side of the first plate and protruding perpendicularly therefrom.The first plurality of fins may be arranged in first concentric circlesseparated radially by a first distance. The apparatus may also include asecond plate having a first side. The second plate may be rotatablycoupled to the first plate. The apparatus may additionally include asecond plurality of fins integral with the first side of the secondplate and protruding perpendicularly therefrom. The second plurality offins may be arranged in second concentric circles separated radially bythe first distance. Each fin of the second plurality of fins mayinterpose between adjacent fins of the first plurality of fins totransfer heat between the second plate and the first plate.

In another embodiment, a system is provided that includes a thermalrotary link. The thermal rotary link may include a first plate having afirst side and a second side opposite the first side. The thermal rotarylink may additionally include a first plurality of fins integral withthe first side of the first plate and protruding perpendicularlytherefrom. The first plurality of fins may be arranged in firstconcentric circles separated radially by a first distance. The thermalrotary link may also include a second plate having a first side and asecond side opposite to the first side. The second plate may berotatably coupled to the first plate. The thermal rotary link mayfurther include a second plurality of fins integral with the first sideof the second plate and protruding perpendicularly therefrom. The secondplurality of fins may be arranged in second concentric circles separatedradially by the first distance. Each fin of the second plurality of finsmay interpose between adjacent fins of the first plurality of fins totransfer heat between the second plate and the first plate. The systemmay also include a rotating heat source thermally connected to thesecond side of the second plate. The system may further include acooling device thermally connected to the second side of the firstplate. The cooling device may be configured to absorb heat transferredfrom the rotating heat source by way of the thermal rotary link.

In a further embodiment, a method is provided that includes conductingheat from a rotating heat source to a first plate. The first plateincludes a first plurality of fins integral with a first side of thefirst plate and protruding perpendicularly therefrom. The firstplurality of fins is arranged in first concentric circles separatedradially by a first distance. The rotating heat source is fixedlyconnected to a second side of the first plate and is in thermal contacttherewith. The method also includes rotating the first plate withrespect to a second plate. The method additionally includes conductingheat from the first plate to the second plate by way of the firstplurality of fins interposing with and rotating with respect to a secondplurality of fins. The second plurality of fins is integral with a firstside of the second plate and protruding perpendicularly therefrom. Thesecond plurality of fins is arranged in second concentric circlesseparated radially by the first distance. Each fin of the secondplurality of fins interposes between adjacent fins of the firstplurality of fins. The method further includes conducting heat from thesecond plate to a cooling device in thermal contact with a second sideof the second plate.

In a yet further embodiment, a system is provided that includes a statormeans having a first side and a first plurality of fin means integralwith the first side of the stator means and protruding perpendicularlytherefrom. The first plurality of fin means may be arranged in firstconcentric circles separated radially by a first distance. The systemmay also include a rotor means having a first side. The rotor means maybe rotatably coupled to the stator means. The system may additionallyinclude a second plurality of fin mean integral with the first side ofthe rotor means and protruding perpendicularly therefrom. The secondplurality of fin means may be arranged in second concentric circlesseparated radially by the first distance. Each fin means of the secondplurality of fin means may interpose between adjacent fin means of thefirst plurality of fin means to transfer heat between the rotor meansand the stator means.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the figures and the followingdetailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an example LIDAR device, accordingto an example embodiment.

FIG. 2 illustrates a simplified block diagram of a vehicle, according toan example embodiment.

FIG. 3 illustrates several views of a LIDAR device positioned on top ofa vehicle, according to an example embodiment.

FIG. 4 illustrates an example heat transfer system including a thermalrotary link, according to an example embodiment.

FIG. 5A illustrates an example rotor, according to an exampleembodiment.

FIG. 5B illustrates an example stator, according to an exampleembodiment.

FIG. 6A illustrates another example rotor, according to an exampleembodiment.

FIG. 6B illustrates another example stator, according to an exampleembodiment.

FIG. 7A illustrates a LIDAR device connected to a thermal rotary link,according to an example embodiment.

FIG. 7B illustrates a cross-section of an exploded view of a thermalrotary link, according to an example embodiment.

FIG. 8 illustrates example operations of a thermal rotary link,according to an example embodiment.

FIG. 9A illustrates a close-up view of a rotor and stator, according toan example embodiment.

FIG. 9B illustrates a temperature difference as a function of heatpower, according to an example embodiment.

FIG. 9C illustrates a temperature difference as a function of rotationspeed, according to an example embodiment.

FIG. 9D illustrates a temperature difference as a function of finheight, according to an example embodiment.

FIG. 9E illustrates a temperature difference as a function of gap widthbetween interposing fins, according to an example embodiment.

FIG. 9F illustrates a temperature difference as a function of a numberof fins, according to an example embodiment.

FIG. 10A illustrates a steady-state temperature of a stationary rotor,according to an example embodiment.

FIG. 10B illustrates a steady-state temperature of a rotating rotor,according to an example embodiment.

FIG. 11 illustrates a sealed chamber enclosing a thermal rotary link,according to an example embodiment.

DETAILED DESCRIPTION

The following detailed description describes various features andoperations of the disclosed devices, systems, and methods with referenceto the accompanying figures. The illustrative device, system, and methodembodiments described herein are not meant to be limiting. It should beunderstood that the words “exemplary,” “example,” and “illustrative,”are used herein to mean “serving as an example, instance, orillustration.” Any implementation, embodiment, or feature describedherein as “exemplary,” “example,” or “illustrative,” is not necessarilyto be construed as preferred or advantageous over other implementations,embodiments, or features. Further, aspects of the present disclosure, asgenerally described herein and illustrated in the figures, can bearranged, substituted, combined, separated, and designed in a widevariety of different configurations.

In the following detailed description, reference is made to theaccompanying figures, which form a part thereof. In the figures, similarsymbols typically identify similar components, unless context dictatesotherwise. Other embodiments may be utilized, and other changes may bemade, without departing from the spirit or scope of the subject matterpresented herein. Further, unless otherwise noted, figures are not drawnto scale and are used for illustrative purposes only. Moreover, thefigures are representational only and not all components are shown. Forexample, additional structural or restraining components might not beshown.

I. OVERVIEW

Provided herein are example embodiments of a thermal rotary link forcreating a thermal connection between two or more devices, systems, orobjects that are configured to rotate with respect to one another. Thethermal rotary link may include a rotor and a stator, each including arespective planar plate and a respective plurality of fins protrudingperpendicularly from the planar plate. The rotor and the stator may berotatably connected by a rotational joint disposed between the plates ofthe rotor and the stator. The rotor and stator may be connected axiallyto rotate about a common axis of rotation defined by the rotationaljoint. In some embodiments, the rotational joint may additionally serveas a conduit for wired or wireless power and data connections betweenthe rotating heat source and a stationary surface to which the stator ofthe thermal rotary link is mounted. The rotor may be thermally andfixedly connected to a heat source and the stator may be thermally andfixedly connected to a cooling device.

The plurality of fins may be arranged in concentric circles such thatthat fins of the rotor may interpose with fins of the stator.Specifically, the finned side of the rotor may face the finned side ofthe stator and each fin of the rotor may fit between and/or next tocorresponding fins of the stator, and vice versa. Notably, the innermostand outermost fins of all the fins on the rotor and the stator mightonly have one neighboring fin. Nonetheless, the fins can be viewed asinterposing with at least one other corresponding fin protruding fromthe opposite plate (i.e., the opposite plate to a fin of the stator isthe plate of the rotor, and vice versa). Each of the remaining fins mayfit between two corresponding adjacent fins on the opposite plate.

The plurality of fins may be designed to increase or maximize a surfacearea exposed between fins of the rotor and fins of the stator. Heat maybe transferred from the fins of the rotor to fins of the stator by wayof an air gap separating adjacent fins when the fins of the rotor andfins of the stator are interposed with one another. The gap may bereduced or minimized to decrease the extent of air or other fluidthrough which heat has to flow to move between fins of the rotor andfins of the stator. Heat may be transferred between the fins viaconduction. Rotation of the rotor with respect to the stator may, insome embodiments, additionally induce convective heat transfer frommotion of the fluid (e.g., air) in the gaps between adjacent fins. Thethermal rotary link may be used to transfer heat from a heat source suchas a rotating LIDAR device to a cooling device.

In one example, the heat source may be a LIDAR device configured torotate about an axis to scan the environment surrounding the LIDARdevice. In order to acquire scans with a sufficient resolution orsignal-to-noise ratio, the power with which the LIDAR device is operatedmight need to be above a threshold power level. However, operating theLIDAR device above the threshold power level may generate excess heatthat the LIDAR device might not be able to dissipate at a ratesufficient to maintain the LIDAR device within a safe operatingtemperature range. The inability to dissipate heat at a sufficient ratemay stem from, for example, a density with which the electrical andoptical components of the LIDAR device are packaged inside the LIDARdevice housing. The example thermal rotary links herein described may beused to transfer excess heat away from the LIDAR device to maintain theLIDAR device at stable operating temperatures even when the LIDAR deviceis operating above the threshold power level. At the same time, thethermal rotary link may provide for rotation of the LIDAR device withrespect to the vehicle or structure to which the LIDAR device ismounted.

In alternative examples, the heat source may be a sensor such as, forexample, a Radio Detection and Ranging (RADAR) device, a SoundNavigation and Ranging (SONAR) device, a camera (e.g., stereo camera,structured light device), or an inertial measurement unit (IMU). Thesensor may be configured to rotate about an axis to scan the environmentsurrounding the sensor. The example thermal rotary links hereindescribed may be used to transfer excess heat away from the sensor tomaintain the sensor at stable operating temperatures may provide forrotation of the sensor with respect to a vehicle or structure to whichthe sensor is mounted.

In some embodiments, the concentric circles in which the fins of therotor and the stator are arranged may be radially offset from oneanother to allow each fin of the plurality of fins of the rotor tointerpose between corresponding adjacent fins of the plurality of finsof the stator, and vice versa. In particular, each of the fins of therotor and the stator may have a uniform first thickness. Adjacentconcentric circles on the rotor may be offset from one another by adistance greater than the first thickness to allow the corresponding finof the stator to fit in between the fins within the adjacent concentriccircles, and vice versa. Additionally, the concentric circles of therotor may be radially offset from corresponding concentric circles ofthe stator by at least the first thickness to prevent the fins on thestator from colliding with the fins of the rotor (even though gapsbetween radially adjacent fins may be large enough to accommodatecorresponding fins). In alternative embodiments, fin thickness may benon-uniform. Radial spacing between concentric circles may vary inproportion to the thickness of the respective fins configured tointerpose therebetween.

In some examples, each of the concentric circles in which the pluralityof fins is arranged may be defined by a single fin. That is, each fin ofthe rotor and the stator may extend continuously about the circumferenceof a respective concentric circle. In alternative examples, two or morefins may extend along portions of the circumference of each respectiveconcentric circle. Angular offsets between fins within a concentriccircle may be configured to generate and allow for convective fluid flowwhen the plurality of fins of the rotor is rotated with respect to theplurality of fins of the stator.

In further embodiments, the rotor and stator may be enclosed in a sealedchamber filled with a thermally conductive fluid. The sealed chamber maybe filled with a gas or liquid that is more thermally conductive thanatmospheric air to improve heat transfer between the rotor and thestator.

In yet further embodiments, a cylindrical space may be defined betweenthe plate of the rotor, the plate of the stator, and the innermost finsof either the rotor or the stator. Disposed within the space may be arotary transformer that provides wireless power to electronic devices onthe rotor side and a stationary power source on the stator side. Thus,power may be transferred across the rotational joint between rotor andstator without using a slip ring. Similarly, data may be transferredwirelessly across the rotational connection by way of one or morewireless modules such as near-field radio frequency coupling units.

II. EXAMPLE LIDAR DEVICES

Referring now to the Figures, FIG. 1 is a simplified block diagram of aLIDAR device 100, according to an example embodiment. As shown, theLIDAR device 100 includes a power supply arrangement 102, electronics104, light source(s) 106, a transmitter 108, a first receiver 110, asecond receiver 112, a rotating platform 114, actuator(s) 116, astationary platform 118, a rotary link 120, and a housing 122. In otherembodiments, the LIDAR device 100 may include more, fewer, or differentcomponents. Additionally, the components shown may be combined ordivided in any number of ways.

Power supply arrangement 102 may be configured to supply power tovarious components of the LIDAR device 100. In particular, the powersupply arrangement 102 may include or otherwise take the form of atleast one power source disposed within the LIDAR device 100 andconnected to various components of the LIDAR device 100 in any feasiblemanner, so as to supply power to those components. Additionally oralternatively, the power supply arrangement 102 may include or otherwisetake the form of a power adapter or the like that is configured toreceive power from one or more external power sources (e.g., from apower source arranged in a vehicle to which the LIDAR device 100 iscoupled) and to supply that received power to various components of theLIDAR device 100 in any feasible manner. In either case, any type ofpower source may be used such as, for example, a battery.

Electronics 104 may include one or more electronic components and/orsystems each arranged to help facilitate certain respective operationsof the LIDAR device 100. In practice, these electronics 104 may bedisposed within the LIDAR device 100 in any feasible manner. Forinstance, at least some of the electronics 104 may be disposed within acentral cavity region of the rotary link 120. Nonetheless, theelectronics 104 may include various types of electronic componentsand/or systems.

For example, the electronics 104 may include various wirings used fortransfer of control signals from a controller to various components ofthe LIDAR device 100 and/or for transfer of data from various componentsof the LIDAR device 100 to the controller. Generally, the data that thecontroller receives may include sensor data based on detections of lightby the receivers 110-112, among other possibilities. Moreover, thecontrol signals sent by the controller may operate various components ofthe LIDAR device 100, such as by controlling emission of light by thetransmitter 106, controlling detection of light by the receivers110-112, and/or controlling the actuator(s) 116 to rotate the rotatingplatform 112, among other possibilities.

In some arrangements, the electronics 104 may also include thecontroller at issue. This controller may have one or more processors,data storage, and program instructions stored on the data storage andexecutable by the one or more processor to facilitate variousoperations. Additionally or alternatively, the controller maycommunicate with an external controller or the like (e.g., a computingsystem arranged in a vehicle to which the LIDAR device 100 is coupled)so as to help facilitate transfer of control signals and/or data betweenthe external controller and the various components of the LIDAR device100.

In other arrangements, however, the electronics 104 may not include thecontroller at issue. Rather, at least some of the above-mentionedwirings may be used for connectivity to an external controller. Withthis arrangement, the wirings may help facilitate transfer of controlsignals and/or data between the external controller and the variouscomponents of the LIDAR device 100. Other arrangements are possible aswell.

Further, one or more light sources 106 can be configured to emit,respectively, a plurality of light beams and/or pulses havingwavelengths within a wavelength range. The wavelength range could be,for example, in the ultraviolet, visible, and/or infrared portions ofthe electromagnetic spectrum. In some examples, the wavelength range canbe a narrow wavelength range, such as provided by lasers. In oneexample, the wavelength range includes wavelengths that areapproximately between 1545 nm and 1555 nm. It is noted that this rangeis described for exemplary purposes only and is not meant to belimiting.

In accordance with the present disclosure, one of the light sources 106may be a fiber laser that includes an optical amplifier. In particular,the fiber laser may be a laser in which an active gain medium (i.e., asource of optical gain within the laser) is in an optical fiber.Moreover, the fiber laser could be arranged in various ways within theLIDAR device 100. For instance, the fiber laser could be disposedbetween the rotating platform 114 and the first receiver 110.

In some arrangements, the one or more light sources 106 may additionallyor alternatively include laser diodes, light emitting diodes (LED),vertical cavity surface emitting lasers (VCSEL), organic light emittingdiodes (OLED), polymer light emitting diodes (PLED), light emittingpolymers (LEP), liquid crystal displays (LCD), microelectromechanicalsystems (MEMS), and/or any other device configured to selectivelytransmit, reflect, and/or emit light to provide the plurality of emittedlight beams and/or pulses.

In some embodiments, transmitter 108 may be configured to emit lightinto an environment. In particular, the transmitter 108 may include anoptical arrangement that is arranged to direct light from a light source106 toward the environment. This optical arrangement may include anyfeasible combination of mirror(s) used to guide propagation of the lightthroughout physical space and/or lens(es) used to adjust certaincharacteristics of the light, among other optical components. Forinstance, the optical arrangement may include a transmit lens arrangedto collimate the light, thereby resulting in light having rays that aresubstantially parallel to one another.

In some implementations, the optical arrangement may also include adiffuser arranged to spread the light along a vertical axis. Inpractice, the diffuser may be formed from glass or another material, andmay be shaped (e.g., aspherical shape) to spread or otherwise scatterlight in a particular manner. For instance, the vertical spread may be aspread of +7° away from a horizontal axis to −18° away from thehorizontal axis (e.g., the horizontal axis ideally being parallel to aground surface in the environment). Moreover, the diffuser may becoupled to a light source 106 in any direct or indirect manner, such asby being fused to an output end of the fiber laser for instance.

Thus, this implementation may result in laser beams or the like havinghorizontal beam width (e.g., 1 mm) that is significantly narrower than avertical beam width of the laser beams. As noted, suchhorizontally-narrow laser beams may help avoid interference betweenbeams reflected off a reflective object and beams reflected off aless-reflective object that is horizontally adjacent to the reflectiveobject, which may ultimately help the LIDAR device 100 distinguishbetween those objects. Other advantages are possible as well.

Yet further, in some implementations, the optical arrangement may alsoinclude a dichroic mirror arranged to reflect at least a portion of thediffused light towards a thermal energy measurement device (not shown)of the LIDAR device 100, which could take the form of a thermopile forinstance. With this implementation, the thermal energy measurementdevice could be arranged to measure energy of the light being emittedtowards the environment. And data related to that energy measurementcould be received by a controller and then used by the controller asbasis for facilitating further operations, such as adjustments tointensity of the emitted light for example. Other implementations arealso possible.

As noted, the LIDAR device 100 may include a first receiver 110 and asecond receiver 112. Each such receiver may be respectively configuredto detect light having wavelengths in the same wavelength range as theone of the light emitted from the transmitter 108 (e.g., 1545 nm to 1555nm). In this way, the LIDAR device 100 may distinguish reflected lightpulses originated at the LIDAR device 100 from other light in theenvironment.

In accordance with the present disclosure, the first receiver 110 may beconfigured to detect light with a first resolution and the secondreceiver 112 may be configured to detect light with a second resolutionthat is lower than the first resolution. For example, the first receiver110 may be configured to detect light with a 0.036° (horizontal)×0.067°(vertical) angular resolution, and the second receiver 112 may beconfigured to detect light with a 0.036° (horizontal)×0.23° (vertical)angular resolution.

Additionally, the first receiver 110 may be configured to scan theenvironment with a first field of view (FOV) and the second receiver 112may be configured to scan the environment with a second FOV that is atleast partially different from the first FOV. Generally, thisarrangement may allow the LIDAR device 100 to scan different portions ofthe environment respectively at different resolutions, which may beapplicable in various situations as further discussed below. Forinstance, the different FOVs of the receivers at issue may be at leastpartially different vertical FOVs that collectively allow for detectionof light substantially along the same angular range as theabove-mentioned vertical spread of the emitted light.

In some implementations, the first receiver 110 may be arranged to focusincoming light within a range of +7° away from the above-mentionedhorizontal axis to −7° away from the horizontal axis, and the secondreceiver 112 may be arranged to focus incoming light within a range of−7° away from the horizontal axis to −18° away from the horizontal axis.In this way, the first and second receivers 110-112 collectively allowfor detection of light along a range of +7° to −18°, which matches theabove-mentioned exemplary vertical spread of light that the transmitter108 provides. It is noted that these resolutions and FOVs are describedfor exemplary purposes only and are not meant to be limiting.

In an example implementation, the first and second receivers 110-112 mayeach have a respective optical arrangement that allows the receiver toprovide the respective resolution and FOV as described above. Generally,each such optical arrangement may be arranged to respectively provide anoptical path between at least one optical lens and a photodetectorarray.

In one implementation, the first receiver 110 may include an opticallens arranged to focus light reflected from one or more objects in theenvironment of the LIDAR device 100 onto detectors of the first receiver110. To do so, the optical lens may have dimensions of approximately 10cm×5 cm as well as a focal length of approximately 35 cm, for example.Moreover, the optical lens may be shaped so as to focus incoming lightalong a particular vertical FOV as described above (e.g., +7° to −7°).Such shaping of the first receiver's optical lens may take on one ofvarious forms (e.g., spherical shaping) without departing from the scopeof the present disclosure.

In this implementation, the first receiver 110 may also include at leastone mirror arranged to fold the optical path between the at least oneoptical lens and the photodetector array. Each such mirror may be fixedwithin the first receiver 110 in any feasible manner. Also, any feasiblenumber of mirrors may be arranged for purposes of folding the opticalpath. For instance, the first receiver 110 may also include two or moremirrors arranged to fold the optical path two or more times between theoptical lens and the photodetector array. In practice, such folding ofthe optical path may help reduce the size of the first receiver, amongother outcomes.

In another implementation, the first receiver 110 may include two ormore optical lenses. For example, the first receiver 110 may include anouter spherically-shaped lens facing the environment as well as an innercylindrically-shaped lens. In this example, incoming light may thus befocused onto a line on a focal plane. Other examples and implementationsare possible as well.

Furthermore, as noted, the first receiver may have a photodetectorarray, which may include two or more detectors each configured toconvert detected light (e.g., in the above-mentioned wavelength range)into an electrical signal indicative of the detected light. In practice,such a photodetector array could be arranged in one of various ways. Forexample, the detectors can be disposed on one or more substrates (e.g.,printed circuit boards (PCBs), flexible PCBs, etc.) and arranged todetect incoming light that is traveling along the optical path from theoptical lens. Also, such a photodetector array could include anyfeasible number of detectors aligned in any feasible manner. Forexample, the photodetector array may include a 13×16 array of detectors.It is noted that this photodetector array is described for exemplarypurposes only and is not meant to be limiting.

Generally, the detectors of the array may take various forms. Forexample, the detectors may take the form of photodiodes, avalanchephotodiodes, phototransistors, cameras, active pixel sensors (APS),charge coupled devices (CCD), cryogenic detectors, and/or any othersensor of light configured to receive focused light having wavelengthsin the wavelength range of the emitted light. Other examples arepossible as well.

With regards to the second receiver 112, the second receiver 112 mayalso include at least one optical lens arranged to focus light reflectedfrom one or more objects in the environment of the LIDAR device 100 ontodetectors of the first receiver 110. To do so, the optical lens may haveany dimensions, focal length, and shaping that help provide for focusingof incoming light along a particular vertical FOV as described above(e.g., −7° to −18°). In some implementations, the second receiver 112may include one or more mirrors arranged to fold the optical pathbetween the second receiver's optical lens and the second receiver'sphotodetector array. Further, the second receiver's photodetector arraymay include any feasible number of detectors arranged in any of the waysdescribed above in the context of the first receiver 110. Otherimplementations are possible as well.

Further, as noted, the LIDAR device 100 may include a rotating platform114 that is configured to rotate about an axis. In order to rotate inthis manner, one or more actuators 116 may actuate the rotating platform114. In practice, these actuators 116 may include motors, pneumaticactuators, hydraulic pistons, and/or piezoelectric actuators, amongother possibilities. In some embodiments, the rotating platform 114 maybe integrated with or may form part of a rotor of a thermal rotary linkdisclosed herein.

In accordance with the present disclosure, the transmitter 108 and thefirst and second receivers 110-112 may be arranged on the rotatingplatform such that each of these components moves relative to theenvironment based on rotation of the rotating platform 114. Inparticular, each of these components could be rotated relative to anaxis so that the LIDAR device 100 may obtain information from variousdirections. In this manner, the LIDAR device 100 may have a horizontalviewing direction that can be adjusted by actuating the rotatingplatform 114 to different directions.

With this arrangement, a controller could direct an actuator 116 torotate the rotating platform 114 in various ways to obtain informationabout the environment in various ways. In particular, the rotatingplatform 114 could rotate at various extents and in either direction.For example, the rotating platform 114 may carry out full revolutionssuch that the LIDAR device 100 provides a 360° horizontal FOV of theenvironment. Thus, given that the first and second receivers 110-112 mayboth rotate based on rotation of the rotating platform 114, bothreceivers 110-112 may have the same horizontal FOV (e.g., 360°) whilehaving different vertical FOV as described above.

Moreover, the rotating platform 114 could rotate at various rates so asto cause LIDAR device 100 to scan the environment at various refreshrates. For example, the LIDAR device 100 may be configured to have arefresh rate of 15 Hz (e.g., fifteen complete rotations of the LIDARdevice 100 per second). In this example, assuming that the LIDAR device100 is coupled to a vehicle as further described below, the scanningthus involves scanning a 360° FOV around the vehicle fifteen times everysecond. Other examples are also possible.

Yet further, as noted, the LIDAR device 100 may include a stationaryplatform 118. In practice, the stationary platform may take on any shapeor form and may be configured for coupling to various structures, suchas to a top of a vehicle for example. Also, the coupling of thestationary platform may be carried out via any feasible connectorarrangement (e.g., bolts and/or screws). In this way, the LIDAR device100 could be coupled to a structure to be used for various purposes,such as those described herein.

In some embodiments, the stationary platform 118 may be integrated withor may form part of a stator of a thermal rotary link disclosed herein.Heat generated by electronic, optical, and mechanical components ofLIDAR device 100 may be transferred away from LIDAR device 100 by way ofthe thermal rotary link. In particular, the thermal rotary link maytransfer heat from the rotating platform 114 to stationary platform 118.Stationary platform 118 may include and/or may be in thermal contactwith a cooling device to absorb heat from the LIDAR device 100.

In accordance with the present disclosure, the LIDAR device 100 may alsoinclude a rotary joint 120 that directly or indirectly couples thestationary platform 118 to the rotating platform 114. Specifically, therotary joint 120 may take on any shape, form and material that providesfor rotation of the rotating platform 114 about an axis relative to thestationary platform 118. For instance, the rotary joint 120 may take theform of a shaft or the like that rotates based on actuation from anactuator 116, thereby transferring mechanical forces from the actuator116 to the rotating platform 114. Moreover, as noted, the rotary jointmay have a central cavity in which electronics 104 and/or one or moreother components of the LIDAR device 100 may be disposed. The rotaryjoint 120 may form part of the thermal rotary link and may provide forrotation of the rotor with respect to the stator. Other arrangements arepossible as well.

Yet further, as noted, the LIDAR device 100 may include a housing 122.In practice, the housing 122 may take on any shape, form, and material.For example, the housing 122 can be a dome-shaped housing, among otherpossibilities. In another example, the housing 122 may be composed of amaterial that is at least partially non-transparent, which may allow forblocking of at least some light from entering the interior space of thehousing 122 and thus help mitigate thermal effects as further discussedbelow. It is noted that this housing is described for exemplary purposesonly and is not meant to be limiting.

In accordance with the present disclosure, the housing 122 may becoupled to the rotating platform 114 such that the housing 122 isconfigured to rotate about the above-mentioned axis based on rotation ofthe rotating platform 114. With this implementation, the transmitter108, the first and second receiver 110-112, and possibly othercomponents of the LIDAR device 100 may each be disposed within thehousing 122. In this manner, the transmitter 108 and the first andsecond receiver 110-112 may rotate along with this housing 122 whilebeing disposed within the housing 122.

Moreover, the housing 122 may have an aperture formed thereon, whichcould take on any feasible shape and size. In this regard, thetransmitter 108 could be arranged within the housing 120 so as to emitlight into the environment through the aperture. In this way, thetransmitter 108 may rotate along with the aperture due to correspondingrotation of the housing 120, thereby allowing for emission of light intovarious directions. Also, the first and second receiver 110-112 couldeach be respectively arranged within the housing 120 so as respectivelydetect light that enters the housing 120 from the environment throughthe aperture. In this way, the receivers 110-112 may rotate along withthe aperture due to corresponding rotating of the housing 120, therebyallowing for detection of the light incoming from various directionsalong the horizontal FOV.

In practice, the housing 122 may be arranged as described above forvarious reasons. Specifically, due to various components of the LIDARdevice 100 being disposed within the housing 122 and due to the housing122 rotating along with those components, the housing 122 may helpprotect those components from various environmental hazards, such asrain and/or snow, among others. Also, if the housing 122 were to bestationary as the LIDAR device 100 rotates within the housing 122, thenthe housing 122 would likely be transparent so as to allow forpropagation of light through the housing 122 and thus for scanning ofthe environment by the LIDAR device 100.

In accordance with the present disclosure, however, the housing 122 mayhave the aperture that rotates along with the LIDAR device 100, whichmeans that the housing 122 does not necessarily need to be fullytransparent to allow for scanning of the scanning of the environment.For example, the housing 122 could be composed of at least a partiallynon-transparent material, except for the aperture, which could becomposed of a transparent material. As a result, the housing 122 mayhelp mitigate thermal effects on the LIDAR device 100. For instance, thehousing 122 may block sun rays from entering the interior space of thehousing 122, which may help avoid overheating of various components ofthe LIDAR device 100 due to those sun rays. Other instances are possibleas well.

Given the various components of the LIDAR device 100 as described above,these various components could be arranged in various ways. Inaccordance with the present disclosure, assuming that the LIDAR device100 is spatially oriented such that the stationary platform 118 isclosest to a ground surface, the LIDAR device 100 may be arranged suchthat (i) the first receiver 110 is positioned substantially above thestationary platform 118, (ii) the second receiver 112 and thetransmitter 108 are both positioned substantially above the firstreceiver 110, and (iii) the second receiver 112 is positionedsubstantially horizontally adjacent to the transmitter 108. However, itis noted that this arrangement is described for exemplary purposes onlyand is not meant to be limiting.

III. EXAMPLE VEHICLE SYSTEM

FIG. 2 is a simplified block diagram of a vehicle 200, according to anexample embodiment. The vehicle 200 may include a LIDAR device similarto the LIDAR device 100. As shown, the vehicle 200 includes a propulsionsystem 202, a sensor system 204, a control system 206 (could also bereferred to as a controller 206), peripherals 208, and a computer system210. In other embodiments, the vehicle 200 may include more, fewer, ordifferent systems, and each system may include more, fewer, or differentcomponents.

Additionally, the systems and components shown may be combined ordivided in any number of ways. For instance, the control system 206 andthe computer system 210 may be combined into a single system thatoperates the vehicle 200 in accordance with various operations.

The propulsion system 202 may be configured to provide powered motionfor the vehicle 200. As shown, the propulsion system 202 includes anengine/motor 218, an energy source 220, a transmission 222, andwheels/tires 224.

The engine/motor 218 may be or include any combination of an internalcombustion engine, an electric motor, a steam engine, and a Sterlingengine. Other motors and engines are possible as well. In someembodiments, the propulsion system 202 may include multiple types ofengines and/or motors. For instance, a gas-electric hybrid car mayinclude a gasoline engine and an electric motor. Other examples arepossible.

The energy source 220 may be a source of energy that powers theengine/motor 218 in full or in part. That is, the engine/motor 918 maybe configured to convert the energy source 220 into mechanical energy.Examples of energy sources 220 include gasoline, diesel, propane, othercompressed gas-based fuels, ethanol, solar panels, batteries, and othersources of electrical power. The energy source(s) 220 may additionallyor alternatively include any combination of fuel tanks, batteries,capacitors, and/or flywheels. In some embodiments, the energy source 220may provide energy for other systems of the vehicle 200 as well.

The transmission 222 may be configured to transmit mechanical power fromthe engine/motor 218 to the wheels/tires 224. To this end, thetransmission 222 may include a gearbox, clutch, differential, driveshafts, and/or other elements. In embodiments where the transmission 222includes drive shafts, the drive shafts may include one or more axlesthat are configured to be coupled to the wheels/tires 224.

The wheels/tires 224 of vehicle 200 may be configured in variousformats, including a unicycle, bicycle/motorcycle, tricycle, orcar/truck four-wheel format. Other wheel/tire formats are possible aswell, such as those including six or more wheels. In any case, thewheels/tires 224 may be configured to rotate differentially with respectto other wheels/tires 224. In some embodiments, the wheels/tires 224 mayinclude at least one wheel that is fixedly attached to the transmission222 and at least one tire coupled to a rim of the wheel that could makecontact with the driving surface. The wheels/tires 224 may include anycombination of metal and rubber, or combination of other materials. Thepropulsion system 202 may additionally or alternatively includecomponents other than those shown.

The sensor system 204 may include a number of sensors configured tosense information about an environment in which the vehicle 200 islocated, as well as one or more actuators 236 configured to modify aposition and/or orientation of the sensors. As shown, the sensors of thesensor system 204 include a Global Positioning System (GPS) 226, aninertial measurement unit (IMU) 928, a RADAR unit 230, a laserrangefinder and/or LIDAR unit 232, and a camera 234. The sensor system204 may include additional sensors as well, including, for example,sensors that monitor internal systems of the vehicle 200 (e.g., an O₂monitor, a fuel gauge, an engine oil temperature, etc.). Other sensorsare possible as well.

The GPS 226 may be any sensor (e.g., location sensor) configured toestimate a geographic location of the vehicle 200. To this end, the GPS226 may include a transceiver configured to estimate a position of thevehicle 200 with respect to the Earth. The GPS 226 may take other formsas well.

The IMU 228 may be any combination of sensors configured to senseposition and orientation changes of the vehicle 200 based on inertialacceleration. In some embodiments, the combination of sensors mayinclude, for example, accelerometers and gyroscopes. Other combinationsof sensors are possible as well.

The RADAR unit 230 may be any sensor configured to sense objects in theenvironment in which the vehicle 200 is located using radio signals. Insome embodiments, in addition to sensing the objects, the RADAR unit 230may additionally be configured to sense the speed and/or heading of theobjects.

Similarly, the laser range finder or LIDAR unit 232 may be any sensorconfigured to sense objects in the environment in which the vehicle 200is located using lasers. For example, LIDAR unit 232 may include one ormore LIDAR devices, at least some of which may take the form the LIDARdevice 100 disclosed herein.

The camera 234 may be any camera (e.g., a still camera, a video camera,etc.) configured to capture images of the environment in which thevehicle 200 is located. To this end, the camera may take any of theforms described above. The sensor system 204 may additionally oralternatively include components other than those shown.

The control system 206 may be configured to control operation of thevehicle 200 and its components. To this end, the control system 206 mayinclude a steering unit 238, a throttle 240, a brake unit 242, a sensorfusion algorithm 244, a computer vision system 246, a navigation orpathing system 248, and an obstacle avoidance system 250.

The steering unit 238 may be any combination of mechanisms configured toadjust the heading of vehicle 200. The throttle 240 may be anycombination of mechanisms configured to control the operating speed ofthe engine/motor 218 and, in turn, the speed of the vehicle 200. Thebrake unit 242 may be any combination of mechanisms configured todecelerate the vehicle 200. For example, the brake unit 242 may usefriction to slow the wheels/tires 224. As another example, the brakeunit 242 may convert the kinetic energy of the wheels/tires 224 toelectric current. The brake unit 242 may take other forms as well.

The sensor fusion algorithm 244 may be an algorithm (or a computerprogram product storing an algorithm) configured to accept data from thesensor system 204 as an input. The data may include, for example, datarepresenting information sensed at the sensors of the sensor system 204.The sensor fusion algorithm 244 may include, for example, a Kalmanfilter, a Bayesian network, an algorithm for some of the functions ofthe methods herein, or any another algorithm. The sensor fusionalgorithm 244 may further be configured to provide various assessmentsbased on the data from the sensor system 204, including, for example,evaluations of individual objects and/or features in the environment inwhich the vehicle 200 is located, evaluations of particular situations,and/or evaluations of possible impacts based on particular situations.Other assessments are possible as well.

The computer vision system 246 may be any system configured to processand analyze images captured by the camera 234 in order to identifyobjects and/or features in the environment in which the vehicle 200 islocated, including, for example, traffic signals and obstacles. To thisend, the computer vision system 246 may use an object recognitionalgorithm, a Structure from Motion (SFM) algorithm, video tracking, orother computer vision techniques. In some embodiments, the computervision system 246 may additionally be configured to map the environment,track objects, estimate the speed of objects, etc.

The navigation and pathing system 248 may be any system configured todetermine a driving path for the vehicle 200. The navigation and pathingsystem 248 may additionally be configured to update the driving pathdynamically while the vehicle 200 is in operation. In some embodiments,the navigation and pathing system 248 may be configured to incorporatedata from the sensor fusion algorithm 244, the GPS 226, the LIDAR unit232, and one or more predetermined maps so as to determine the drivingpath for vehicle 200.

The obstacle avoidance system 250 may be any system configured toidentify, evaluate, and avoid or otherwise negotiate obstacles in theenvironment in which the vehicle 200 is located. The control system 206may additionally or alternatively include components other than thoseshown.

Peripherals 208 may be configured to allow the vehicle 200 to interactwith external sensors, other vehicles, external computing devices,and/or a user. To this end, the peripherals 208 may include, forexample, a wireless communication system 252, a touchscreen 254, amicrophone 256, and/or a speaker 258.

The wireless communication system 252 may be any system configured towirelessly couple to one or more other vehicles, sensors, or otherentities, either directly or via a communication network. To this end,the wireless communication system 252 may include an antenna and achipset for communicating with the other vehicles, sensors, servers, orother entities either directly or via a communication network. Thechipset or wireless communication system 252 in general may be arrangedto communicate according to one or more types of wireless communication(e.g., protocols) such as Bluetooth, communication protocols describedin IEEE 802.11 (including any IEEE 802.11 revisions), cellulartechnology (such as GSM, CDMA, UMTS, EV-DO, WiMAX, or LTE), Zigbee,dedicated short range communications (DSRC), and radio frequencyidentification (RFID) communications, among other possibilities. Thewireless communication system 252 may take other forms as well.

The touchscreen 254 may be used by a user to input commands to thevehicle 200. To this end, the touchscreen 254 may be configured to senseat least one of a position and a movement of a user's finger viacapacitive sensing, resistance sensing, or a surface acoustic waveprocess, among other possibilities. The touchscreen 254 may be capableof sensing finger movement in a direction parallel or planar to thetouchscreen surface, in a direction normal to the touchscreen surface,or both, and may also be capable of sensing a level of pressure appliedto the touchscreen surface. The touchscreen 254 may be formed of one ormore translucent or transparent insulating layers and one or moretranslucent or transparent conducting layers. The touchscreen 254 maytake other forms as well.

The microphone 256 may be configured to receive audio (e.g., a voicecommand or other audio input) from a user of the vehicle 200. Similarly,the speakers 258 may be configured to output audio to the user of thevehicle 200. The peripherals 208 may additionally or alternativelyinclude components other than those shown.

The computer system 210 may be configured to transmit data to, receivedata from, interact with, and/or control one or more of the propulsionsystem 202, the sensor system 204, the control system 206, and theperipherals 208. To this end, the computer system 210 may becommunicatively linked to one or more of the propulsion system 202, thesensor system 204, the control system 206, and the peripherals 208 by asystem bus, network, and/or other connection mechanism (not shown).

In one example, the computer system 210 may be configured to controloperation of the transmission 222 to improve fuel efficiency. As anotherexample, the computer system 210 may be configured to cause the camera234 to capture images of the environment. As yet another example, thecomputer system 210 may be configured to store and execute instructionscorresponding to the sensor fusion algorithm 244. As still anotherexample, the computer system 210 may be configured to store and executeinstructions for determining a 3D representation of the environmentaround the vehicle 200 using the LIDAR unit 232. Other examples arepossible as well. Thus, the computer system 210 could function as thecontroller for the LIDAR unit 232.

As shown, the computer system 210 includes the processor 212 and datastorage 214. The processor 212 may comprise one or more general-purposeprocessors and/or one or more special-purpose processors. To the extentthe processor 212 includes more than one processor, such processorscould work separately or in combination. Data storage 214, in turn, maycomprise one or more volatile and/or one or more non-volatile storagecomponents, such as optical, magnetic, and/or organic storage, and datastorage 214 may be integrated in whole or in part with the processor212.

In some embodiments, data storage 214 may contain instructions 216(e.g., program logic) executable by the processor 212 to execute variousvehicle functions (e.g., methods 500, etc.). Data storage 214 maycontain additional instructions as well, including instructions totransmit data to, receive data from, interact with, and/or control oneor more of the propulsion system 202, the sensor system 204, the controlsystem 206, and/or the peripherals 208. The computer system 210 mayadditionally or alternatively include components other than those shown.

As shown, the vehicle 200 further includes a power supply 220, which maybe configured to provide power to some or all of the components of thevehicle 200. To this end, the power supply 220 may include, for example,a rechargeable lithium-ion or lead-acid battery. In some embodiments,one or more banks of batteries could be configured to provide electricalpower. Other power supply materials and configurations are possible aswell. In some embodiments, the power supply 220 and energy source 220may be implemented together as one component, as in some all-electriccars.

In some embodiments, the vehicle 200 may include one or more elements inaddition to or instead of those shown. For example, the vehicle 200 mayinclude one or more additional interfaces and/or power supplies. Otheradditional components are possible as well. In such embodiments, datastorage 214 may further include instructions executable by the processor212 to control and/or communicate with the additional components.

Still further, while each of the components and systems are shown to beintegrated in the vehicle 200, in some embodiments, one or morecomponents or systems may be removably mounted on or otherwise connected(mechanically or electrically) to the vehicle 200 using wired orwireless connections. The vehicle 200 may take other forms as well.

FIG. 3 shows a Right Side View, Front View, Back View, and Top View ofthe vehicle 300. As shown, the vehicle 300 includes the LIDAR device 100being positioned on a top side of the vehicle 300 opposite a bottom sideon which wheels 302 of the vehicle 300 are located. Although the LIDARdevice 100 is shown and described as being positioned on the top side ofthe vehicle 300, the LIDAR device 100 could be positioned on any partfeasible portion of the vehicle without departing from the scope of thepresent disclosure.

Moreover, the LIDAR device 100 may be configured to scan an environmentaround the vehicle 300 (e.g., at a refresh rate of 15 Hz) by rotatingabout the vertical axis while emitting one or more light pulses anddetecting reflected light pulses off objects in the environment of thevehicle 300, for example.

IV. EXAMPLE THERMAL ROTARY LINK SYSTEM

FIG. 4 illustrates a cross-section of an example thermal rotary linkapparatus for transferring heat from a heat source 406 to a coolingdevice 408 (e.g., cold plate). The thermal rotary link may include arotor 400 connected to a stator 402 through a rotational joint 404.Rotational joint 404 may provide for rotation of rotor 400 with respectto stator 402. Heat source 406 may be thermally and/or mechanicallycoupled to rotor 400 by way of coupling 410. Similarly, cooling device408 may be thermally and/or mechanically coupled to stator 402. Stator402 and rotor 400 may each include a plurality of fins protrudingperpendicularly therefrom. The plurality of fins of the rotor and thestator may be arranged in concentric circles radially offset from oneanother by distances that provide for the plurality of fins of thestator 402 to interpose with the plurality of fins of the rotor 400 totransfer heat from rotor 400 to stator 402.

Thus, the thermal rotary link may provide a thermally conductiverotational connection between heat source 406 and cooling device 408. Ingeneral, the thermal rotary link may be used to transfer heat betweenany devices, objects, or systems that are in rotational motion withrespect to one another. For example, such a thermal rotary connectionmay be useful for cooling a rotating heat source such as a rotatingLIDAR device.

Within examples, heat source 406 could be a LIDAR device or anyelectronic, optical, mechanical, or electromechanical device, system, orobject that generates heat during operation either intentionally or as abyproduct. Cooling device 408 may be any active or passive device orsystem configured to absorb and/or dissipate heat. Heat source 406 maybe at a higher temperature than cooling device 408 to induce heat flowfrom the heat source 406 to the cooling device 408.

FIG. 5A illustrates a side cross-sectional view aligned with acorresponding top view of rotor 400. In one embodiment, rotor 400 mayinclude a planar circular plate, as shown in the top view of FIG. 5A.However, in other embodiments, the rotor may include a planar plate invarious other regular or irregular geometric shapes (e.g., rectangle,ellipse, octagon, etc.). A plurality of fins 500, 501, 502, 503, 504,505, 506, 507, 508, and 509 (i.e., fins 500-509) may be integral withand may protrude perpendicularly from one side of the plate. Withinexamples, “planar” and “perpendicular” are herein defined to encompassdeviations from exact planarity and exact perpendicularity,respectively, resulting from (i) variations in tolerances ofmanufacturing processes employed in production of components of thesystem, (ii) deflections and other structural deviations resulting fromstresses during normal operation of the system, and (iii) any otherdeviations that do not hinder or prevent the operations of the thermalrotary link herein described.

The plurality of fins 500-509 may be arranged in concentric circles, asillustrated in the top view of rotor 400. In some embodiments, each finof the plurality of fins 500-509 may extend continuously about thecircumference of a respective concentric circle. Thus, in thecross-sectional view, the leftmost and rightmost fin 500, for example,may be a single fin extending about the circumference of the circularplate forming rotor 400.

Rotor 400 and fins 500-509 may comprise a metallic material with a highthermal conductivity such as aluminum or copper. In some exampleembodiments, the rotor 400 and the plurality of fins 500-509 may bemanufactured as one piece by, for example, forging, die casting,milling, or turning on a lathe, among other possibilities. Inalternative embodiments, the plate and the plurality of fins 500-509 maybe manufactured as separate pieces that may be welded, swaged,press-fitted, screwed, glued, stamped, and/or bolted together.Regardless of the manufacturing process employed, the plurality of fins500-509 may be fixedly connected to (i.e., be integral with) the planarplate of rotor 400 to establish thermal contact between the plurality offins 500-509 and the plate.

In some example embodiments, rotor 400 may include mounting holes 510 a,510 b, 510 c, and 510 d for interfacing the rotor 400 with the heatsource 406. Mounting holes 510 a-510 d may provide for mounting of rotor400 to heat source 406 directly or by way of coupling 410. Inalternative implementations, the size, number, and spacing of mountingholes 510 a-510 d may be tailored to the specific type and size of heatsource 406.

FIG. 5B illustrates a side cross-sectional view aligned with acorresponding top view of stator 402. Much like rotor 400, stator 402may, in one example embodiment, include a planar circular plate, asshown in the top view of FIG. 5B. However, in other embodiments, therotor may include a planar plate in various other regular or irregulargeometric shapes. A plurality of fins 512, 513, 514, 515, 516, 517, 518,519, 520, and 521 (i.e., fins 512-521) may be integral with and mayprotrude perpendicularly from one side of the plate of stator 402.

The plurality of fins 512-521 may be arranged in concentric circles, asillustrated in the top view of stator 402. In some embodiments, each finof the plurality of fins 500-509 may extend continuously about thecircumference of a respective concentric circle. Like rotor 400, stator402 and fins 512-521 thereof may comprise a metallic material with ahigh thermal conductivity such as aluminum or copper. The stator 402 andthe plurality of fins 512-521 may be manufactured as one piece or asmultiple pieces that are fixedly joined together, as described above.Regardless of the manufacturing process employed, the plurality of fins512-521 may be fixedly connected to (i.e., be integral with) the planarplate of stator 402 to establish thermal contact between the pluralityof fins 512-521 and the plate.

In some example embodiments, stator 402 may include mounting holes 522a, 522 b, 522 c, and 522 d for interfacing the stator 402 with thecooling device 408. Mounting holes 510 a-510 d may provide for mountingof stator 402 to cooling device 408 directly or by way of coupling 412.In alternative implementations, the size, number, and spacing ofmounting holes 522 a-522 d may be tailored to the specific type and sizeof cooling device 408.

When rotor 400 and stator 402 are rotatably connected to one another,the plurality of fins 500-509 of the rotor 400 may interpose with theplurality of fins 512-521 of the stator 402, as shown in FIG. 4.Specifically, the fins arranged in adjacent circles on rotor 400 may beradially separated from one another to allow corresponding fins ofstator 402 to interpose therebetween. For example, the radial gapbetween fins 500 and 501 of rotor 400 may be sufficient to permitcorresponding fin 512 of stator 402 to interpose therebetween. Likewise,the radial gap between fins 501 and 502 of the rotor 400 may besufficient to permit corresponding fin 513 of stator 402 to interposetherebetween. On the stator side, the radial gap between fins 512 and513, for example, may be sufficient to permit corresponding fin 501 ofrotor 400 to interpose therebetween.

In some embodiments, the radial distance separating fins of adjacentconcentric circles may be uniform across all fins 500-509 of rotor 400and all fins 512-521 of stator 402. Thus, each of fins 500-509 and512-521 may also have a uniform width. However, in some alternativeembodiments, fin width and radial gap width may be varied across fins500-509 and 512-521. For example, fin 513 of stator 402 may be widerthan fin 512. Accordingly, to accommodate the larger fin 513, the gapbetween fins 501 and 502 of rotor 400 may be larger than the gap betweenfins 500 and 501 corresponding to fin 512. Thus, in general, the radialgap between two fins in adjacent circles may be proportional to a widthof a corresponding fin configured to interpose therebetween. The radialgap may additionally provide a clearance between the interposing fins toreduce or eliminate friction during rotation of the rotor 400 withrespect to stator 402. In one example, the radial gap may be 300microns.

The interposition of fins 500-509 of rotor 400 with fins 512-521 ofstator 402 may form a thermally conductive path that may provide forheat flow from heat source 406 to cooling device 408. In particular,heat may flow from heat source 406, through coupling 410, to rotor 400and fins 500-509 thereof. Heat may then flow from fins 500-509 of rotor400 to fins 512-521 of stator 402 by way of an air gap between theinterposing fins. Further, heat may flow from fins 512-521 to the plateof stator 402 and through coupling 412 to be absorbed by cooling device408. Thus, since rotor 400 may rotate with respect to stator 402 aboutjoint 404, the thermal rotary link may be used to dissipate heat from arotating heat source such as a LIDAR device that may need cooling to bemaintained at a stable operating temperature.

In some embodiments, stator 402, as implied by the name, may beconnected to a stationary, non-rotating device, surface, or object.Rotor 400 may rotate with respect to stationary stator 402. However, inalternative embodiments, rotor 400 and stator 402 may both rotate withrespect to one another. For example, rotor 400 and stator 402 may rotatein opposite directions or may rotate in the same direction at differentrates. Further, although rotor 400 is illustrated in FIG. 4 as beinglarger than stator 402, in some alternative embodiments stator 402 maybe larger than rotor 400.

V. ALTERNATIVE FIN ARRANGEMENTS

In some embodiments, two or more fins may be included within a singleconcentric circle, as illustrated in FIGS. 6A and 6B. Specifically, thefins within each concentric circle of rotor 600 may be separated byangular offsets defined by radial cuts 604, 606, 608, 610, 612, 614,616, and 618. Thus, each concentric circle may include therein eightdiscontinuous fins. Likewise, fins within each concentric circle ofstator 602 may be separated by angular offsets defined by radial cuts620, 622, 624, 626, 628, 630, 632, and 634. Each fin may have the samecurvature as the respective concentric circle about the circumference ofwhich it is arranged. In some embodiments, cuts 604-634 may formpatterns other than straight lines such as, for example, splines. Thus,the angular position of the angular offsets may vary between differentconcentric circles.

In some embodiments, the angular offsets may help generate convectivefluid flow in response to rotation of rotor 600 and the plurality offins thereon with respect to stator 602 and the plurality of finsthereon. Specifically, when the relative rotation speed between therotor 600 and stator 602 exceeds a threshold speed, the fluid flowbetween the interposing fins may become turbulent, thus increasing theextent of convective heat transfer. Accordingly, heat may be removedfrom the heat source by conduction as well as convection and therelative contribution of each effect to the total heat transfer may varywith the relative speed of rotation between the rotor and the stator.Further, the pattern of cuts 604-634 (e.g., linear radial lines,splines, etc.) may be selected to increase or maximize turbulence toincrease the extent of convective heat transfer.

VI. EXAMPLE THERMAL ROTARY LINK FOR LIDAR DEVICE

FIG. 7A illustrates an example thermal rotary link for transferring heataway from a rotating LIDAR device. Rotor 702 is shown connected to thebottom of the housing of LIDAR device 704. LIDAR device 704 may be thesame as or similar to LIDAR device 100 of FIG. 1. Heat-producingcomponents within the housing of LIDAR device 704 may be in thermalcontact with the top of the plate of rotor 702. Rotor 702 includes onthe underside thereof a plurality of fins (not shown) configured tointerpose with the plurality of fins of stator 700. Rotor 702 mayconnect to stator 700 by way of a rotational joint system that includesrods/shafts 708 and 714. Stator 700 may be mounted to a cooling device(not shown) to absorb the heat transferred from LIDAR 704 by way of thethermal rotary link.

The LIDAR, thermal rotary link, and cooling device may be mounted to avehicle configured for autonomous operation based on data from the LIDARdevice. For example, the LIDAR may be mounted on the roof of thevehicle, hood of the vehicle, doors of the vehicle, or trunk of thevehicle. In some embodiments, multiple LIDAR devices may be included onthe vehicle, each providing information about a particular region aroundthe vehicle. Further, in some examples, portions of the LIDAR device,the thermal rotary link, and/or the cooling device may be located insidethe vehicle frame.

The rotational joint system may include rods/shafts 708 and 714. Stator700 may include a circular hole 706 concentric with the axis of rotationof the stator 700. A first end of hollow rod 708 may be connectable tostator 700 by way of one or more screws or bolts. In some embodiments,stator 700 and rod 708 may be manufactured as one piece. Rod 708 mayprotrude through the circular hole 706, in the same direction as thefins, such that a second end of rod 708 is connectable to rotor 702, asillustrated in FIG. 7A. Rod 714 may have a smaller diameter than rod 708and may thus fit within rod 708. A first end of rod 714 may be rigidlyconnectable to rotor 702 and/or LIDAR 704.

One or more bearings may be used to rotatably mount rod 714 inside ofrod 708. A motor may be connected to rod 714 to rotate rod 714 withrespect to rod 708, thus rotating rotor 702 and LIDAR 704 with respectto stator 700. In some embodiments, the motor may be configured torotate rotor 702 and stator 704 at a rate dictated by the dataacquisition rate of the LIDAR device. A plurality of wires includingpower and data connections may pass through rods 708 and 714 to connectthe LIDAR device to a power source and a computing device (e.g., acomputing device configured to autonomously operate a vehicle based ondata from the LIDAR device). One or more slip rings may be includedwithin the rotational joint system to transfer power and data throughthe rotational connection. In some embodiments, power transfer may relyon the slip rings while data may be transferred to the computing devicewirelessly.

FIG. 7B illustrates a cross-section of an exploded view of anotherexample thermal rotary link. The thermal rotary link may include astator comprising a first plate 722 and a first plurality of fins 724protruding perpendicularly from a first side of plate 722. Further, thethermal rotary link may include a rotor comprising a second plate 720and a second plurality of fins 726 protruding perpendicularly from afirst side of plate 724. The first and second pluralities of fins 724and 726 may be arranged in concentric circles spaced to allow the firstplurality of fins 724 to interpose with the second plurality of fins726, as previously described.

A first hollow shaft 736 may be connected to plate 722 of the stator.Hollow shaft 736 may include therein a guide rod 736. A second hollowshaft 728 may be connected to plate 720 of the rotor. Shaft 728 mayinclude therein bearings 730 and 732 to provide for rotation of hollowshaft 728 about guide rod 734. The inner bore diameter of shaft 736 maycorrespond to an outer diameter of shaft 728 to accommodate shaft 728inside shaft 736. Shaft 736 may extend away from the finned side ofplate 722 through to the non-finned side. Thus, when shaft 728 isdisposed about guide rod 734 within shaft 736, the first plurality offins 724 may be vertically positioned to interpose with the plurality offins 726.

FIG. 7B further illustrates rotary transformer windings 740 a and 740 bdisposed within a cavity defined by plates 720 and 722 and the innermostfins of the pluralities of fins 724 and 726. Specifically, thetransformer includes a secondary winding 740 a that rotates with respectto a stationary primary winding 740 b to transfer power across therotational connection between the stator to the rotor without using sliprings. Additionally, a motor configured to drive the rotor (and the heatsource connected thereto) with respect to the stator may be disposedwithin the cavity. In particular, the motor may include motor windings738 b connected to the stator and permanent magnets 738 a connected tothe rotor. The windings 738 b are connected to the stator, as opposed tothe rotor, so that energy to power the motor is not transferred throughthe rotational connection via rotary transformer 740 a/740 b (thusallowing for a smaller rotary transformer).

VII. EXAMPLE THERMAL ROTARY LINK OPERATIONS

FIG. 8 illustrates flow diagram 800 of example operations that may beperformed by an example thermal rotary links discussed herein. Theoperations may be performed to transfer heat between two devices,systems, or objects that are in rotational motion with respect to eachother. Heat may be transferred by a combination of conduction andconvection through a fluid-filled gap between interposing fins of thethermal rotary link, thus allowing the relative rotational motionbetween the heat source and the cooling device. In some implementations,heat may be transferred primarily through conduction.

In block 802, heat may be conducted from a rotating heat source to afirst plate. The first plate may include a first plurality of finsintegral with a first side of the first plate and protrudingperpendicularly therefrom. The first plurality of fins may be arrangedin first concentric circles separated radially by a first distance. Therotating heat source may be fixedly connected to a second side of thefirst plate and may be in thermal contact therewith. The first plate andthe first plurality of fins may collectively make up the rotor portionof the thermal rotary link.

In block 804, the first plate may be rotated with respect to a secondplate. The rotation may be caused by, for example, a motor and may beabout a rotational joint connecting the first plate to the second plate.In some embodiments, the first and second plates may each be planarcircular plates configured to rotate about an axis through the center ofeach plate. In some examples, the rate of rotation of the first platewith respect to the second plate may determine the extent of convectiveheat transfer. In particular, rotation of the first plate with respectto the second plate at a rate of speed greater than a threshold speedmay create turbulent, as opposed to laminar, fluid flow within thethermal rotary link, thus improving convective heat transfer.

In block 806, heat may be conducted from the first plate to the secondplate by way of the first plurality of fins interposing with androtating with respect to a second plurality of fins. The secondplurality of fins may be integral with a first side of the second plateand protruding perpendicularly therefrom. The second plurality of finsmay be arranged in second concentric circles separated radially by thefirst distance. Each fin of the second plurality of fins may interposebetween adjacent fins of the first plurality of fins. The second plateand the second plurality of fins may collectively make up the statorportion of the thermal rotary link.

In block 808, heat may be conducted from the second plate to a coolingdevice in thermal contact with a second side of the second plate. Thecooling device may be any device or object at a temperature lower thanthe heat source and capable of absorbing and/or dissipating the heattransferred from the heat source. The cooling device may be, forexample, a cold plate or a radiator.

VIII. EXAMPLE THERMAL ROTARY LINK PERFORMANCE CHARACTERISTICS

FIG. 9A illustrates example parameters of the thermal rotary link thatmay be varied to control the rate of heat transfer between rotor 900 andstator 902. In particular, heat transfer between rotor 900 and stator902 may be affected by fin width, fin height, and the radial gap betweenadjacent fins. Further, heat transfer may be affected by the number offins on the rotor and on the stator. These parameters may collectivelyaffect the extent of surface area on the fins of the rotor and thestator through which heat can be transferred. FIGS. 9B, 9C, 9D, 9E, and9F detail the effects of the individual parameters on the heat transfercapacity of the thermal rotary link.

FIG. 9B illustrates the capacity of an example thermal rotary link totransfer heat between the heat source and the cooling device acrossdifferent heat loads. In particular, FIG. 9B graphs a real-worldtemperature difference measured between the plates of the rotor and thestator across different heat loads for an example thermal rotary linkthat includes 10 fins on each of the rotor and the stator, a fin widthof 1 millimeter, a fin height of 10 millimeters, and a gap of 300microns between the interposed fins across all fins. FIG. 9B illustratesthat the temperature difference between the rotor and the statorincreases linearly in proportion to the heat applied by the heat source.In particular, for each additional Watt of power, the temperaturedifference increases by 0.133° C. (with a y-intercept of −1.36° C.).Thus, for example, in order to maintain the rotor plate connected to aheat source expected to produce 120 Watts of heat power at an operatingtemperature below 50° C., a cooling device capable of maintaining atemperature below 35° C. could be used in the system.

FIG. 9C illustrates the capacity of the thermal rotary link describedwith respect to FIG. 9B to transfer heat between the heat source and thecooling device across different rotational speeds. FIG. 9C representsreal world experimental data. In particular, a decrease in thetemperature difference between the rotor and stator may be gained byincreasing the rotation speed of the rotor with respect to the stator.However, the scaling is nonlinear and exhibits diminishing returns forlarge increases in rotational speed above zero rotations per minute(RPM). In other words, the marginal benefit of each additional RPMdecreases in proportion to the current RPM of the rotor. Thus, inimplementations where rotor RPM is a manipulable variable, an optimumRPM may be selected that weighs the added cooling benefit of increasedrotation speed against the increased power expenditure to maintain therotation speed based on the particular application of the thermal rotarylink. In the example embodiment of the rotating LIDAR device describedabove, the rotor RPM may be fixed to the rotational speed dictated bythe rotating LIDAR device.

FIG. 9D illustrates the capacity of an example thermal rotary link totransfer heat between the heat source and the cooling device acrossdifferent fin heights. In particular, FIG. 9D graphs a simulatedtemperature difference between the plates of the rotor and the statoracross different fin heights for an example thermal rotary link thatincludes 15 fins on each of the rotor and the stator, a fin width of 1millimeter, and a gap of 300 microns between the interposed fins under aheat load of 150 Watts. The temperature difference decreases nonlinearlyas fin height is increased. In particular, the marginal benefit of anincrease in fin height decreases in proportion to fin height.

FIG. 9E illustrates the capacity of an example thermal rotary link totransfer heat between the heat source and the cooling device acrossdifferent gap widths between the interposing fins. In particular, FIG.9E graphs a simulated temperature difference between the plates of therotor and the stator across different gap widths for an example thermalrotary link that includes 15 fins on each of the rotor and the stator, afin width of 1 millimeter, and a fin height of 15 millimeters under aheat load of 150 Watts. The temperature difference increases linearly asthe gap width is increased. In particular, an increase of 1 micron ingap width contributes an increase of 0.03° C. in temperature difference.

FIG. 9F illustrates the capacity of an example thermal rotary link totransfer heat between the heat source and the cooling device acrossdifferent numbers of fins. In particular, FIG. 9D graphs a simulatedtemperature difference between the plates of the rotor and the statoracross different numbers of fins for an example thermal rotary link thatincludes a fin width of 1 millimeter, a fin height of 15 millimeters,and a gap width of 300 microns between the interposed fins under a heatload of 150 Watts. The temperature difference decreases nonlinearly asthe number of fins is increased. In particular, the marginal benefit ofeach additional fin decreases in proportion to the number of fins.

Parameters of the thermal rotary link such as gap width, number of fins,fin height, and fin width may be determined in combination withconsiderations of manufacturing tolerances, cost, size limitations, androbustness of the thermal rotary link to damage and deformations duringnormal use. The relationships illustrated in FIGS. 9A-9F may be used toadapt the example thermal rotary links herein described to otherapplications.

FIGS. 10A and 10B illustrate the effects of rotation of the rotor withrespect to the stator on the steady-state temperature at the rotorplate. In particular, FIGS. 10A and 10B graph a real-world rotor platetemperature measured over time for a thermal rotary link including 17fins with a height of 13 millimeters, a width of 1 millimeter, and a gapwidth between interposed fins of 300 microns under a heat load of 150Watts. FIG. 10A shows that a stationary rotor settles to a steady-statetemperature of approximately 55.6° C. FIG. 10B illustrates that spinningthe rotor with respect to the stator contributes an additional decreaseof 2.1° C. in the steady-state temperature of the rotor. Thus, the rotorreaches a steady state temperature of 53.5° C. when rotating withrespect to the stator.

IX. ADDITIONAL EXAMPLE THERMAL ROTARY LINK EMBODIMENTS

FIG. 11 illustrates an example thermal rotary link disposed within asealed chamber. In particular, similarly to FIG. 4, FIG. 11 illustratesa heat source 1106 connected to a cooling device 1108 through a thermalrotary link that includes rotor 1100, stator 1102, and rotational joint1104 connecting rotor 1100 to stator 1102. Further, coupling 1110 maymechanically and thermally connect heat source 1106 to rotor 1100.Similarly, coupling 1112 may mechanically and thermally connect coolingdevice 1108 to stator 1102.

The sealed chamber 1114 enclosing the rotor 1100 and stator 1106 may befilled with a thermally conductive fluid other than atmospheric air tomaintain thermal contact between the fins of the rotor and the fins ofthe stator. In particular, the sealed chamber may be filled with a gasthat is more thermally conductive than oxygen such as, for example,helium (Helium thermal conductivity 0.138 W/mK, atmospheric air thermalconductivity 0.024 W/mK). Alternatively, the sealed chamber may befilled with a liquid that is more conductive than atmospheric air suchas, for example, a mixture of water and ethylene glycol. The increasedconductivity may be weighed against the increase in drag caused by thefluid during rotation of the rotor 1100 with respect to stator 1102 inselecting a fluid with which to fill the sealed chamber.

X. CONCLUSION

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its spirit and scope, as will be apparentto those skilled in the art. Functionally equivalent methods andapparatuses within the scope of the disclosure, in addition to thoseenumerated herein, will be apparent to those skilled in the art from theforegoing descriptions. Such modifications and variations are intendedto fall within the scope of the appended claims.

The above detailed description describes various features and functionsof the disclosed systems, devices, apparatuses, and methods withreference to the accompanying figures. In the figures, similar symbolstypically identify similar components, unless context dictatesotherwise. The example embodiments described herein and in the figuresare not meant to be limiting. Other embodiments can be utilized, andother changes can be made, without departing from the spirit or scope ofthe subject matter presented herein. It will be readily understood thatthe aspects of the present disclosure, as generally described herein,and illustrated in the figures, can be arranged, substituted, combined,separated, and designed in a wide variety of different configurations,all of which are explicitly contemplated herein.

A block that represents a processing of information may correspond tocircuitry that can be configured to perform the specific logicalfunctions of a herein-described method or technique. Alternatively oradditionally, a block that represents a processing of information maycorrespond to a module, a segment, or a portion of program code(including related data). The program code may include one or moreinstructions executable by a processor for implementing specific logicalfunctions or actions in the method or technique. The program code and/orrelated data may be stored on any type of computer readable medium suchas a storage device including a disk or hard drive or other storagemedium.

The particular arrangements shown in the figures should not be viewed aslimiting. It should be understood that other embodiments can includemore or less of each element shown in a given figure. Further, some ofthe illustrated elements can be combined or omitted. Yet further, anexample embodiment can include elements that are not illustrated in thefigures.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. An apparatus comprising: a first plate having a first side; a first plurality of fins integral with the first side of the first plate and protruding perpendicularly therefrom, the first plurality of fins arranged in first concentric circles separated radially by a first distance; a second plate having a first side and a second side opposite the first side, wherein the second plate is rotatably coupled to the first plate, and wherein the second side is fixedly connected to a heat source to maintain thermal contact between the second plate and the heat source, wherein the heat source comprises an electronic device; a second plurality of fins integral with the first side of the second plate and protruding perpendicularly therefrom, the second plurality of fins arranged in second concentric circles separated radially by the first distance, wherein each fin of the second plurality of fins interposes between adjacent fins of the first plurality of fins to transfer heat between the second plate and the first plate; a chamber defined between the first side of the first plate, the first side of the second plate, and innermost fins of the first plurality of fins and the second plurality of fins; and a transformer disposed within the chamber, wherein the transformer is configured to provide wireless power to the electronic device and comprises (i) a primary winding connected to the first plate and (ii) a secondary winding connected to the second plate.
 2. The apparatus of claim 1, wherein each fin of the first plurality of fins and the second plurality of fins has a first thickness, and wherein each of the second concentric circles is radially offset from each of the first concentric circles by at least the first thickness to allow each fin of the second plurality of fins to interpose between adjacent fins of the first plurality of fins.
 3. The apparatus of claim 1, wherein each fin of the first and second pluralities of fins extends continuously about the circumference of a respective concentric circle.
 4. The apparatus of claim 1, wherein two or more fins extend along portions of the circumference of each respective concentric circle of the first concentric circles and the second concentric circles, and wherein a gap between adjacent fins of the two or more fins is configured to generate convective fluid flow in response to rotation of the second plurality of fins with respect to the first plurality of fins.
 5. The apparatus of claim 1, wherein the electronic device is a light detection and ranging (LIDAR) device, and wherein the second plate is configured to rotate with respect to the first plate to cause rotation of the LIDAR device.
 6. The apparatus of claim 1, wherein the first plate comprises a second side opposite the first side, wherein the second side of the first plate is fixedly connectable to a cooling device to maintain thermal contact between the first plate and the cooling device.
 7. The apparatus of claim 1, wherein the first plate comprises a circular hole concentric with the first plate, further comprising: a rod rigidly connected at a first end thereof to the first plate, the rod protruding through the circular hole, wherein the second plate is rotatably connected to the first plate by way of a rotatable connection of the second plate to a second end of the rod.
 8. The apparatus of claim 1, further comprising: a sealed chamber enclosing the first plate and the second plate, wherein the first plate and the second plate are disposed within the sealed chamber with the first plurality of fins interposed with the second plurality of fins.
 9. The apparatus of claim 8, wherein the sealed chamber is filled with a thermally conductive fluid to maintain thermal contact between the first plurality of fins and the second plurality of fins.
 10. The apparatus of claim 1, wherein the first plate, the second plate, the first plurality of fins, and the second plurality of fins comprise a metallic material.
 11. The apparatus of claim 1, further comprising: a motor disposed within the chamber and configured to rotate the second plate with respect to the first plate, the motor comprising: one or more motor windings connected to the first plate; and one or more magnets connected to the second plate.
 12. The apparatus of claim 5, further comprising: a vehicle configured for autonomous operation based on data from the LIDAR device, wherein the LIDAR device is mounted to the vehicle by way of the first plate and the second plate.
 13. A system, comprising: a thermal rotary link comprising: a first plate having a first side and a second side opposite the first side; a first plurality of fins integral with the first side of the first plate and protruding perpendicularly therefrom, the first plurality of fins arranged in first concentric circles separated radially by a first distance; a second plate having a first side and a second side opposite to the first side, wherein the second plate is rotatably coupled to the first plate; and a second plurality of fins integral with the first side of the second plate and protruding perpendicularly therefrom, the second plurality of fins arranged in second concentric circles separated radially by the first distance, wherein each fin of the second plurality of fins interposes between adjacent fins of the first plurality of fins to transfer heat between the second plate and the first plate; a rotating heat source thermally connected to the second side of the second plate, wherein the rotating heat source comprises an electronic device; a cooling device thermally connected to the second side of the first plate, the cooling device configured to absorb heat transferred from the rotating heat source by way of the thermal rotary link; a chamber defined between the first side of the first plate, the first side of the second plate, and innermost fins of the first plurality of fins and the second plurality of fins; and a transformer disposed within the chamber, wherein the transformer is configured to provide wireless power to the electronic device and comprises (i) a primary winding connected to the first plate and (ii) a secondary winding connected to the second plate.
 14. The system of claim 13, wherein the electronic device comprises a light detection and ranging (LIDAR) device fixedly connected to the second side of the second plate, and wherein the second plate is configured to rotate with respect to the first plate to cause rotation of the LIDAR device.
 15. The system of claim 14, further comprising: a vehicle configured for autonomous operation based on data from the LIDAR device, wherein the cooling device, the thermal rotary link, and the LIDAR device are mounted to the vehicle.
 16. The system of claim 13, wherein each fin of the first plurality of fins and the second plurality of fins has a first thickness, and wherein each of the second concentric circles is radially offset from each of the first concentric circles by at least the first thickness to allow each fin of the second plurality of fins to interpose between adjacent fins of the first plurality of fins.
 17. The system of claim 13, wherein each fin of the first and second pluralities of fins extends continuously about the circumference of a respective concentric circle.
 18. The system of claim 13, wherein two or more fins extend along portions of the circumference of each respective concentric circle of the first concentric circles and the second concentric circles, and wherein a gap between adjacent fins of the two or more fins is configured to generate convective fluid flow upon rotation of the second plate with respect to the first plate. 